The 15th Suggestion: Butting Heads (相容れねえ, Aiirenē) is the fifteenth chapter of the series Medaka Box.

Summary

Shiranui is seen walking around school with Zenkichi, bags of food in her hands. While the two debate what to eat after school, they run into Onigase, who chastises Shiranui for eating in the halls. Shiranui swallows all of the food, much to Onigase's ire. When Onigase goes after Shiranui, Shiranui pushes Zenkichi on top of her, before giving the other girl a brief warning and running off. Onigase tries to give chase, only for Zenkichi to warn her that Shiranui is more untouchable than Medaka. Onigase ignores him, only to discover that they have been handcuffed together. When Zenkichi presses her for the key, she tries unsuccessfully to change the topic, before angrily admitting that she doesn't have one. After Zenkichi upsets her with the implications of their situation however, Onigase decides to lead him to the Public Morals Committee's office, where the key is kept. Trying to distract himself from the awkwardness of the situation, Zenkichi question Onigase as to whether there are really people after her. Onigase admits that she is being targeted by the Mokkin Team, a pair of delinquents each wielding a baseball bat. The pair run into Medaka, who misinterprets their situation as the two of them working together to form a bond between the Student Council and the Public Morals Committee. Zenkichi asks Medaka if she can pick the handcuff lock, which she agrees to. Medaka first handcuffs herself to Zenkichi, so as to see how the locking mechanism works. She then tries to pick the handcuffs, only to find the lock beyond her, much to Zenkichi's and Onigase's displeasure.

As all three head to the Public Morals Committee's office, Medaka stops them several times to help other students. Onigase quickly gets annoyed with Medaka's multiple stops, prompting Zenkichi to point out how much different things are now that they are with Medaka. Onigase shamefully admits that since becoming an Enforcer, she has lost all of her friends. Zenkichi tries to comfort her, only to be angrily rebuked. Medaka notices the Mokkin Team in hiding and calls them out. The pair attack Onigase, believing her movements sealed due to the handcuffs. Onigase tells Zenkichi and Medaka to get behind her, as it is her job to protect them. Zenkichi and Medaka instantaneously defeat the Mokkin Team, Zenkichi telling Onigase that there is no one she needs to protect, while Medaka asks Onigase why they need to get behind her, as there is nothing for the enforcer to do. Seeing that Medaka was capable of breaking a metal bat, Onigase asks Medaka why the other girl couldn't just break the handcuffs. Medaka then asks if it was okay to break them, prompting both Zenkichi and Onigase to slump in defeat.

In the Public Morals Committee's office, Yobuko reports to Unzen about Onigase's two successive failures. Though she suggests they punish her, Unzen tells her to let it go, and asks after Medaka. Yoboku goes on to describe Medaka as a saint, and notes that her suggestion box is extremely popular. Unzen agrees that he has heard that much himself, but insists that she is still their biggest problem. Punching a hole through his PSP with his finger, he goes on to state that mercy and truth are like oil and water.